Reciprocal rafter assembly

 

In my mind this is what the 12 five inch diameter 8 foot long fence posts will look like in a few days.

In case you’re wondering, like I did, this is the machine used by the people I got the untreated fence posts from looks like. Pretty wicked and very noisy when in operation.

With my fresh load of 12 tamerack fence posts loaded I could begin the process. 

I am not going to go into all the details for designing and calculating a reciprocal roof rafter. Spend a few hours on google and you can see how it is done. But I will say that if the idea of designing and laying out a truss for a hip rafter scares you then a reciprocal roof will be more difficult.

With the rim joists layed out and leveled the first rafter is put in place. The Charlie stick is in place and holding the rafter at the correct pitch angle for the roof. All this is based on the calculations using the diameter of the posts and the “Rummy” (look it up) distance used. 

All the posts were layed out. The lower end of the first rafter was tied to the rim with twine. Now the lay up could begin.
 

Posts would be added and tied to the rim. The last post, number 12, would be slid under the first post, number 1. This would require that the number 1 post be jacked up to allow this. Tricky…

Needless to say it did not go well on the first couple of tries. 

But after a few adjustments and fine tuning on the pitch and Charlie stick success was had. Doing all this with the posts 8 feet in the air at the top of the gazebo would be a real killer if you know what I mean!

The next day it was time to begin the steps to anchor the rafters in place. First the posts were secured to the rim joist with 10” GRK screws.

Now with the bottom ends secure I could drill the holes for the bolts that would lock in place the top ends of each rafter. This would require several steps for each hole and need to be repeated 12 times.

Each hole would need to be located so that it went through the center of both the top and bottom post it sits on. This was no small task and required several visual observations from different angles to make sure it was good. The drill guide used for the framing holes was a big help.

Several different drill bits and parts were used in the process as you can see. I “built” a work table to keep all these tools handy but still had to make many, many trips up and down the ladder and out of the frame squeezing between rafters to do it. 

Here is the small stud bolt that I put in the bottom of each post to help locate, and hold the correct position on the mating post below it during assembly. This stud bolt needed to be removed before I drilled or it would kill my 3/4” auger bit. 

Here are the steps I needed to do for each hole -

1 - Jack up post with handyman jack.

2 - Remove stud bolt.

3 - Lower post and remove jack

4 - Position drill guide and secure to post with GRK screws.

5 - Drill 3/4” hole through top and bottom post.

6 - Change to 2”diameter counter bore bit. 

7 - Counter bored 3/4” hole to match length of 3/4”dia.  12” long ready bolt. 

8 - Change to 15/16” dia. Bit.

9 - Enlarge 3/4”dia hole to 15/16” diameter.

10 - Install 3/4” bolt washers and nuts.

11 - Change back to 3/4” dia. Bit

- Repeat process.

I just had to remember to perform step #3 twelve times!

Well so much for that. #$@%!^&@ I remembered step #3  10 times and then sure enough drilled right into the stud bolt I forgot to remove. My mother would say it was enough to make a preacher swear.

 

And after all that here it is all bolted up. With all the posts and rafter numbered. Re-assembly when the ground thaws this spring should go well. Until then I’ll be working on making the pegs to put the frame together on the shaving horse.